1. Technical Field
The present invention relates to a fluid ejection device and a fluid stirring method for the same, and to a fluid storage device and a fluid stirring method for the same.
2. Related Art
Inkjet-type printers as fluid ejection devices have small size and high quality and are rapidly gaining in popularity. Pigment-based ink (fluid) in which minute pigment particles are suspended also has high reflection density and excellent image quality on normal paper, and is therefore widely used. However, when pigment ink is stored statically for a long time, the pigment particles precipitate out of the solvent, and a layer of high pigment concentration occurs at the bottom of the ink tank.
For example, titanium dioxide pigment having high weather resistance is preferred for use as a white inkjet ink, but the titanium dioxide pigment rapidly precipitates and aggregates, due to the high specific gravity thereof with respect to the solvent, thereby creating significant problems with storage stability.
Japanese Registered Utility Model No. 3039583 and Japanese Registered Utility Model No. 3048835 disclose techniques whereby a spherical stirrer is placed inside an ink tank to agitate the ink tank.
Japanese Laid-Open Patent Publication No. 2009-045944 discloses a technique whereby a moving body for stirring is provided inside an ink chamber, the moving body for stirring is retained by magnetism during printing, and during stirring, the moving body for stirring is moved in conjunction with movement of a cartridge which includes the ink chamber.